Mosquitoes are vectors of multiple viral pathogens, a large number of which are RNA viruses. Strategies for viral control may target the vector itself or the interaction between the virus and the vector. This application is based upon the hypothesis that RNA viruses have evolved specific mechanisms for evading the mRNA turnover machineries of the mosquito cell and therefore mRNA decay factors may represent a novel target for therapeutics. Our current knowledge of mRNA decay in insects is minimal thus the primary goals of this proposal must be to elucidate the factors and pathways involved in mRNA turnover in the Aedes mosquito and characterize their regulation. Using an in vitro approach that we have successfully adapted to mosquito cell extracts along with in vivo assays, the goal of Aim I is to characterize the processes of mRNA deadenylation, decapping and decay in mosquitoes. In Aim II we will use this knowledge to gain insights into mechanisms of regulated mRNA decay mediated by togavirus 3'untranslated regions that we have observed. The final aim of the application will address the underlying mechanisms responsible for how non- polyadenylated viral RNAs avoid degradation upon entry into the mosquito cell. In summary, this information will provide fundamental insights into insect molecular biology and virus-host interactions that will provide the groundwork for novel avenues of arbovirus control.